Defibrillator and control circuit



United States Patent 3,442,269 DEFIBRILLATOR AND CONTROL CIRCUIT WalterS. Druz, Oakbrook, Ill., assignor to Zenith Radio Corporation, Chicago,Ill., a corporation of Delaware Filed Dec. 20, 1965, Ser. No. 515,018Int. Cl. A61b 19/00 US. Cl. 128-419 6 Claims ABSTRACT OF THE DISCLOSUREThere is described control circuitry for use in adefibrillator-cardioscope unit which circuitry displays substantialpatient and equipment protective features. Specifically, means areprovided for triggering the defibrillator with a synchronizing signaldeveloped from and in a predetermined phase relation to the patientsheart beat to deliver a single defibrillation impulse to the patient andfor coincidentally inhibiting further effective operation of thetriggering signal source. There is also provided a selector switchhaving a plurality of control positions for variously interrelating theoperation of the defibrillator and the cardioscope to provide safe,simplified operation of the combined unit.

Specification The present invention relates to adefibrillator-cardioscope unit and, more particularly, to controlcircuitry displaying substantial patient and equipment protectivefeatures for use therein.

A defibrillator is a well-known medical electronic device useful interminating fibrillation of the heart, that is, an uncontrolled orarhythmic expansion and contraction of various groups of heart muscles.This state may be induced by accidental electric shock or by severestress as in the case of surgical operations, heart attacks, drowningsor the like. When encountered, prompt and effective counter-measure mustbe taken if the patient is to survive. It is well-known thatdefibrillation, or reinstitution of rhythmic muscle operation in theheart, may be achieved by the application of a controlled electric shockthereto and a number of devices for this purpose have been proposed.

One device which has proven particularly well suited to this end inextensive clinical testing, and which is further adapted for portableemergency on-the-site use is illustrated and claimed in a copendingapplication of Walter S. Druz, Ser. No. 291,703, filed July 1, 1963, nowPatent No. 3,258,013, and assigned to the same assignee as the presentinvention. In the Druz application, there is shown an electronicdefibrillator energized from a wholly self-contained battery powersupply and comprising an inverter and a full-wave rectifier forconverting low voltage battery energy to high voltage energy which isstored in a delay line pulsing circuit. The delay line circuit includesa plurality of capacitors for storing a predetermined electrical chargeand inductive means for appropriate shaping of the waveform ondischarge. In operation, the delay line is charged over a predeterminedperiod of time to accumulate the necessary energy and then dischargedover a relatively short time interval through a pair of electrodesplaced at spaced locations on opposite sides of the patients heart.

For various reasons, it has been found desirable to associate in thesame enclosure with the defibrillator a cardioscope and to interrelatein certain respects operaice tion of these devices. For instance, it isoften desirable to visually monitor the patients heart beat before andafter defibrillation. In certain cases of mild arhythmia of the heartsuch as in atrial fibrillation, i.e., a condition in which the atrialchambers of the heart beat at a rate different from that of theventricles, the patient is not in mortal danger but to restore the heartto proper efiicient operation it is believed by many to be necessary toapply the defibrillation impulse in a predetermined time relation withthe heart beat to avoid possible institution of severe fibrillation.Also, in correlating the equipment in these respects, it is essential,for obvious reasons, to avoid unduly complicating operation of thedevice for the technician and it is highly desirable to incorporateinherent patient and equipment safety features.

It is therefore an object of the present invention to provide controlcircuitry for operatively interrelating, in a predetermined fashion, adefibrillator and cardioscope.

It is a further object of the present invention to provide an improveddefibrillator-cardioscope unit displaying significant patient andequipment safety features.

It is another object of the present invention to provide a controlmechanism for correlating operation of a defibrillator and cardioscopewhich is relatively simple for the average technician to operate, evenunder the stress of an emergency.

In accordance with the invention, there is provided an electronicdefibrillator-cardioscope, operable from a direct current energy source,which comprises first capacitor means for toring high voltage electricalenergy supplied from a direct current source, a pair of defibrillatorelectrodes and switch means normally coupling the first capacitor meansto the direct current source but actuable to couple the first capacitormeans to the electrodes. The cardioscope portion of the system includesa cardiac signal amplifier for developing an amplified output of thebeat of a patients heart and a synchronizing signal amplifier, coupledto the cardiac amplifier, for developing triggering signals in apredetermined phase relation to the beat of the patients heart. Controlcircuitry is provided in the form of actuating means, coupled to thesynchronizing signal amplifier, and responsive to a triggering signalfor operating the switch means and inhibiting means, responsive to theactuation of the switch means by the actuating means, for preventingfurther effective operation of the synchronizing signal amplifier.

In accordance with further aspects of the invention, there is provided aselector switch having a plurality of control positions for variouslyinterrelating operation of the defibrillator and cardiscope, andapparatus for providing safe, simplified operation of the combined unit.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The invention,together with further objects and advantages thereof, may best beunderstood by reference to the following description taken in connectionwith the accompanying drawing, the single figure of which is a schematiccircuit diagram of a preferred embodiment of thedefibrillator-cardioscope unit of the invention.

Referring now to the figure, there is shown in the upper left-handportion of the drawing a portable battery operated defibrillator and inthe upper right-hand portion of the drawing a cardioscope, these unitsbeing intercoupled in accordance with the invention by a four positionselector switch (lower right-hand portion of drawing) and a controlcircuit shown within dashed outline 10.

More particularly, the illustrated defibrillator comprises an inverter11 energized from a self-contained battery supply 12 through the closedcontacts of an onoff switch 13. Switch 13, illustrated in its onposition, is operated by a control knob 15 preferably located on thefront control panel of the defibrillator-cardioscope en closure.Inverter 11 is also provided with an output to the primary of a step-uptransformer lfi, the secondary winding of transformer E being coupled toa full-wave rectifier 17. Rectifier 17 is in turn normally coupled to anenergy storage means 18 through a fixed contact 20 and a movablearmature 21 of a switch means or relay 22 having its energizing coil 82within control circuit 10. Preferably energy storage means 18constitutes a delay line discharge pulsing circuit having firstcapacitor means for storing high voltage electrical energy and aplurality of inductors for appropriately shaping the discharge waveformfrom the storage capacitors. A pair of electrodes 23 and 24 are coupledrespectively to a grounded output terminal 25 of delay line 18 and afixed contact 27 of relay 22. The electrodes are adapted to be appliedto the body of a patient at spaced locations on opposite sides of theheart during operation of the defibrillator. In the mode of operation ofthe defibrillator independent of the cardioscope portion of the unit,relay 22 is operated, to displace movable armature 21 to fixed contact27 and apply the stored defibrillation energy across the electrodes, byclosure of a pair of series connected normally open switches 29 and 30,the actuating members of which are conveniently positioned in therespective insulative handles of the electrodes 23 and 24, asschematically indicated by the dotted lines in the drawing.

The defibrillator also preferably includes a transistorized sensingcircuit 32 having an input taken across output terminals 25 and 26 ofdelay line 18 and an output from a lead 33 to control circuit 10. Aswill be explained more fully hereinafter, sensing circuit 32 monitorsthe voltage across the output terminals of delay line 18 and develops acontrol signal to operate a relay, having an energizing coil 59 Withincontrol circuit and a contact pair 35 coupled to inverter 11, foralternately enabling and disabling inverter 11 to maintain the chargestored in delay line 18 at a preselected value over a prolonged timeinterval.

The structural details of inverter 11, rectifier 17, delay line 18 andsensing circuit 32 are not illustrated as they are not of essentialmoment to the subject invention and for present purposes may be of anysuitable, known construction. However, a preferred embodiment of thesecircuits for providing a defibrillation waveform of a unique and highlyeffective duration, energy content and waveshape is disclosed andclaimed in the aforementioned Druz application.

The cardioscope portion of the unit comprises a cardiac signal amplifier37 having an input from leads 39 and 40 which are coupled to electrodespositioned on opposite sides of the patients heart. For instance, oneelectrode may be applied to the left ankle of the patient while theother is applied to his right wrist. Amplifier 37 develops a balancedoutput with respect to a ground or reference potential which output isapplied to the vertical deflection plates of a cathode ray tube displaysystem Q. The horizontal deflection plates of the cathode ray tube areprovided with a relatively low frequency scanning voltage from ahorizontal sweep circuit 42. Details of circuit 42 and the electron beamfocusing, intensity control apparatus, etc. for oscilloscope 4 1 are notshown for the sake of simplicity, but it is understood that thisapparatus may be of conventional, known construction.

One terminal of cardiac amplifier 37 also provides an input for asynchronizing signal amplifier, indicated generally within the dashedoutline 44 of the drawing. Amplifier 44 includes a diode 46 for clippingthe peak portion of the cardiac signal and substantially conventionaltransistor amplifying circuitry including -NPN amplifier transistors 48and 112, the latter being coupled to an NPN emitter follower outputtransistor Q. The collector electrode of transistor 4 9 is returned asan input to cardiac signal amplifier 37 through a diode 51 to permit,under proper circumstances, display of the synchronizing signalconjointly with the cardiac signal on the screen of oscilloscope 4 1.

The defibrillator is controlled and the operation of the cardioscope anddefibrillator are interrelated by control circuit 10 and a four positionfunction selector switch. The selector switch is shown in the drawing tocomprise a pair of wafer sections 53 and 54, respectively designated asthe function selector wafer and the power control wafer, ganged on 'acommon control shaft for operation from a single control knob 56 locatedon t he front control panel of the defibrillator-cardioscope enclosure.Each wafer is conventional in construction having a fixed outer segmentwith contact points spaced about its periphery and a movable innersegment, usually referred to as a rotor, carrying one or more contactsegments, as shown.

Specifically, control circuit 10 comprises a NPN transistor ii having aninput to its base electrode from lead 33 of voltage sensing circuit 32.The collector electrode of transistor includes the parallel combinationof a capacitor 60 and a relay energizing coil 59 for operating contactpair 35, as indicated in the drawing by the dashed line joining contacts35 and coil 59. The remaining terminal of coil 59 is returned to batterypower supply 12 through a fixed contact 61 and a movable relay armature62, normally positioned to engage contact 61. The emitter electrode oftransistor Q is directly coupled to the collector electrode of anormally non-conductive PNP transistor 6 5 which in turn has its emitterelectrode returned to battery 12 through a diode 64 coupled in serieswith the emitter-base junction of transistor 65 and poled in the samedirection as this junction. A voltage dividing network comprising seriesconnected resistors 66 and 67, having their common junction coupled tothe base of transistor Q, is connected from battery supply 12 through acontact segment shunting adjacent contact points 68 and 69 of waferswitch 53 and through series electrode switches 29 and 30 to ground or asource of reference potential. Concurrent closure of switches 29 and 30to apply a ground at one terminal of resistor 67 develops a biaspotential at the base of transistor Q suflicient to render itconductive. Transistor 5 has an additional input to its base electrodethrough a resistor 70 coupled to the collector electrode of a normallynonconductive transistor switch E. The base electrode of transistor 2 iscoupled to its grounded emitter electrode through a resistor 72 and to acontact point 74 on wafer switch 53 through a series resistor-capacitornetwork 76, 77.

The collector electrode of transistor in addition to being coupled tothe emitter electrode of transistor g, is also coupled to ground throughthe parallel combination of a capacitor 79, a transient suppressingdiode and an energizing coil 82 adapted to operate movable armature 21of relay 22, as shown schematically in the drawing by the dashed linejoining these elements. The collector of transistor 5 is coupled tofurther circuitry through the anode of diode 84. Specifically thecathode of diode 84 is coupled to the collector electrode of transistor48 of synchronizing signal amplifier 44 by a capacitor 85 shunted toground and a diode 86, poled to conduct with diode 84. The cathode ofdiode 84 is also coupled to a fixed relay contact 88 through a resistor89 and to a contact point 91 on wafer switch 53 through the parallelcombination of capacitor 93 an an energizing coil 94 for movablearmature 62. An adjacent contact point 95 on wafer 53 is grounded.

The cardioscope portion of the combined unit is ikewise coupled to aplurality of contact points on wafers 53 and 54 of the function Selectorswitch. Specifically, horizontal sweep circuit 42 and cardiac signalamplifier 37 are coupled to a contact point 96 of power supply wafer 54while synchronizing signal amplifier 44 is coupled to an adjacentcontact point 97 thereon. A contact point 98 of wafer 54 is coupled tothe positive terminal of battery 12. A signal output of sync amplifier44, taken at the mid-point of a voltage dividing network 99 coupled tothe emitter electrode of transistor Q, is connected to a contact point100 of wafer 53. Contact point 100 is also coupled to ground through anormally closed contact of a manually operated switch 101, located onthe front control panel of the defibrillator-cardioscope unit, toeffectively suppress the sync signal output.

In explaining the operation of the circuit of the invention, it willinitially be assumed that the defibrillator portion of the combined unitis in an on condition with the delay line undergoing charging and thatthe cardioscope is in an off condition. Thus, switch 13 is closed andcontrol knob 56 is in its off position both as illustrated in thedrawing and the various relays and switches are also in the positionsdepicted in the drawing. In this condition, direct current from battery12 energizes a transistorized square-wave oscillator within inverter 11to generate an alternating current voltage of square or rectangularwaveform at a frequency of about 800 cycles per second. This voltage isamplified within inverter 11 by a push-pull power amplifier and theamplified alternating voltage output is stepped-up to a higher voltageby stepup transformer 1 (i and impressed on full-wave bridge rectifier17 to supply direct current at a higher voltage than that of battery 12.This output from the high voltage direct current source comprisingbattery 12, inverter 11 and rectifier 17 is employed to charge thestorage condensers of delay line 18 to a voltage which may exceed 3200volts.

Transistorized sensing circuit 32 meters the voltage across the outputterminals of delay line 18 and applies a control signal at the base oftransistor Q. Conduction of transistor energizes relay coil 59 andoperates its contacts 35 thereby alternately enabling and disablingoperation of the inverter to maintain the voltage of the delay line at aconstant preselected value over a long period of time despite leakagecurrents, etc. As taught in the aforementioned Druz application, closureof relay contacts 35 removes a reverse bias on the power amplifiertransistors within unit 11 and permits them to operate in conventionalfashion; however, any use of relay contacts 35 to permit inhibiting ofthe operation of the inverter is satisfactory for purposes of thepresent disclosure and accordingly the circuit is not illustrated indetail.

In closed chest utilization of the defibrillator, electrode 23 is placedon the right border of the sternum just below the sternal notch whileelectrode 24 is placed on the mid-clavicular line near the fifthinterspace, with the heart approximately midway between. For internaluse, following thoracectomy, the electrodes may be applied directlyacross the heart itself. Upon ascertaining that the energy stored in thedelay line is at the requisite level determined by the attendingphysician, switches 29 and 30, located within the respective handles ofelectrodes 24 and 23, are closed to apply a ground potential throughcontact points 69 and 68 of wafer 53 to one terminal of resistor 67. Theresultant decrease in base voltage of transistor tfi renders itconductive and applies essentially the battery 12 voltage acrossenergizing coil 82 to displace its armature 21 to fixed contact 27 anddischarge the energy stored within the delay line through the electrodesand the heart of the patient to accomplish defibrillation. Conduction oftransistor {i5 als applies battery potential to the emitter electrode oftransistor Q thereby inhibiting effective operation of the sensingcircuit 32 to operate inverter 11 during the interval of defibrillation.It has been found that if inverter 11 is permitted to operate duringthis period, the resultant high open circuit voltage developed withinthe power amplifier and across rectifier bridge 17 might severely damagethis apparatus. The circuit just described inherently inhibits such fromoccurring if coil 82 is energized to operate the defibrillator and thusprovides an important and fail-safe equipment protection feature. Upontermination of the defibrillating impulse, the handle switches inelectrodes 23 and 24 are released to restore the apparatus to its normalcharging condition.

When the function selector control knob 56 is moved to its on positionindicated in the drawing, the contact portion of wafer 54 is oriented toelectrically couple contact points 98 and 96 to apply an operatingpotential to cardiac signal amplifier 37 and horizontal sweep circuit 42and, although not shown in the drawing in the interest of simplicity,power is also applied to the electron gun structure of oscilloscope Q.With electrocardiograph electrodes 39 and 40 properly positioned inspaced locations on opposite sides of the patients heart, ashereinbefore described, a visual display of the electrical activity of apatients heart is provided on the screen of the oscilloscope. Theoperation of the defibrillator is still identical to that previouslydescribed and there is no interrelation of the operation of thedefibrillator and cardioscope in this function position. In fact,control knob 15 of the defibrillator may be manipulated to remove powerfrom the defibrillator without in any respect hindering operation of thecardioscope. Thus, the units may be operated totally independently ofone another, and are provided with separate operating controls for thispurpose in the interest of simplicity and safety.

With the function control knob 56 rotated to the position designatedsync in the drawing, the single contact strip on wafer 54 electricallycouples contact points 96, 97 and 98, thus also supplying power tosynchronizing signal amplifier 44. The contact section of wafer 53previously connecting contacts 68 and 69 is rotated clear of thesepoints thereby rendering defibrillator handle switches 29 and 30ineffective. No other electrical contacts are made. In the syncposition, operation is again identical to that described for the onposition excepting only that synchronizing signal amplifier 44 isrendered operative and that the defibrillator can no longer be operated.Thus, the peak portion of the cardiac signal is clipped by diode 46,amplified by transistors :18 and 12 and applied as an additional inputto cardiac signal amplifier 37 through a diode 51. Thus synchronizingpulse appears as a sharp spike on the R wave of the ECG waveform on thedisplay screen of oscilloscope 51. Preferably the synchronizing signalpulse is phased with respect to the beat of the patients heart such asto occur either on the peak or trailing portion of the QRS complex ofthe electrocardiograph. The synchronizing pulse also would be developedat the midpoint of voltage divider .99 of the sync amplifier except forthe ground potential applied to this .point through normally closed,manually operated switch 101. The synchronizing signal is ultimatelycalculated to trigger operation of the defibrillator in a timed relationto the patients heart beat, but for reasons of safety the sync positionis provided to permit the technician to clearly establish that thesynchronizing signal amplifier is working properly before coupling tothe defibrillator.

Movement of the function control knob 56 to the convert positionmaintains the same electrical contacts on wafer 54 as previouslydescribed for the sync position; however, on Wafer 53, contact point 91and grounded contact point are coupled by one contact segment whilecontact points 74 and are joined by a second segment. Thus, a ground isapplied at one terminal of energizing coil 94 and a conductiveconnection is made from the midpoint of a voltage divider network 99 tothe base electrode of normally non-conductive transistor switch 11.However, the synchronizing signals are still not effective to operatetransistor 7 1 because of the ground shunt for these signals provided byswitch 101.

Once the attending physician has determined that all is in order, thepatients heart arhythmia may be electrically converted by depression ofmanually operated switch 101 to permit application of the nextsucceeding synchronizing signal pulse to the base of transistor 21through coupling network 76, 77. This action renders transistor 3conductive and transistor Qi is in turn rendered conductive to developsubstantially the battery supply voltage at its collector electrode.Thus, coil 82 of relay 22 is energized to permit discharge of the energystored within delay line 18 through defibrillator electrodes 23 and 24and the patient, while transistor is inhibited from further effectiveoperation, all as previously discussed. Also, because of the ground atcontact point 91, coil 94 is energized from the battery supply potentialat the collector of transistor Q and moves its associated armature 62 tofixed contact 88 thereby concurrently establishing a holding circuit forit self and applying a forward bias to diode 86. Forward biasing ofdiode 86 couples signal shunting capacitor 85 to the collector electrodeof transistor 4 8 of sync amplifier 44 to inhibit further effectiveoperation of the synchronizing signal amplifier. Since contact 62 isdisengaged from contact 61, relay 59 cannot be energized and contacts 35remain open, thereby preventing the delay line from recharging.

Diode 84 prevents application of the holding circuit potential to coil82 and to the emitter of transistor Q. Thus, transistor 8 and coil 82are restored to their normal condition after a time interval determinedby the duration of the sync inpulse and the time constant of theassociated control circuitry. However, the previously described holdingcircuit continues to preclude further effective operation of thesynchronizing signal amplifier 44 and this amplifier can only berestored to its prior operative condition by manipulating control knob56 back to the sync position. This is an important safety feature assuccessive coupling of the delay line to the patient would dischargeenergy from a partially charged delay line through the patient with thepossible result of reinstituting fibrillation in the heart. Also, forsafety, switch 101 is physically separated from the function selectorswitch and is also preferably seated in a shallow well on the frontcontrol panel of the unit to avoid accidental operation. Thus, there hasbeen shown new and unique control circuitry for interrelating theoperation of the cardioscope and defibrillator in a manner that providesfor simplified operation by a technician, as is essential in emergencycircumstances, and also provides maximum patient and equipmentprotective features which are operative substantially independent of thecare or skill of the operator.

While a particular embodiment of the invention has been shown anddescribed, it will be obvious to those skilled in the art that changesand modifications may be made Without departing from the invention inits broader aspects, and, therefore, the aim in the appended claims isto cover all such changes and modifications as fall within the truespirit and scope of the invention.

I claim:

1. An electronic defibrillator operable from a direct current energysource comprising:

first capacitor means for storing high voltage electrical energysupplied from said direct current source;

a. pair of defibrillator electrodes;

switch means normally coupling said first capacitor means to said directcurrent source but operable to couple said first capacitor means to saidelectrodes;

a cardiac signal amplifier having an input circuit adapted to be coupledto a patient for developing an amplified output of electrical activityof the beat of the patients heart;

a synchronizing signal amplifier having an input circuit coupled to saidcardiac amplifier and having an output circuit, for developingtriggering signals in a predetermined phase relation to the beats of thepatients heart;

a manually operable control switch in said output circuit of saidsynchronizing signal amplifier;

actuating means coupled to said output circuit and responsive to apredetermined one of said triggering signals following operation of saidcontrol switch for operating said switch means to deliver a singledefibrillatory impulse to the patient;

inhibiting means including a circuit coupled to said control switch andresponsive to said predetermined triggering signal for disabling saidsynchronizing signal amplifier and preventing reactuation of said switchmeans, whereby the patient is protected against undesired application ofadditional defibrillatory impulses;

and reset means operable to release said inhibiting means. 2. Thecombination according to claim 1 and further comprising manuallycontrolled means normally precluding response of said actuating means tosaid triggering signals but operable to permit response of saidactuating means thereto, and wherein said inhibiting means includes atriggering signal bypass capacitor, a diode, and means forforward-biasing said diode during operation of said inhibiting means tocouple said triggering signal bypass capacitor to said synchronizingsignal amplifier.

3. The combination according to claim 1 and further comprising a cathoderay tube display system having one display axis coupled to both saidcardiac signal amplifier and said synchronizing signal amplifier forproviding a visual display of the electrical activity of the beats ofthe patients heart and the phase relation of said triggering signalsthereto.

4. The combination according to claim 3 and further comprising adefibrillator-cardioscope selector switch having one operating positionfor coupling said amplifiers only to said cathode ray tube displaysystem and a second operating position for in addition coupling saidsynchronizing signal amplifier to said actuating means, and meansincluding a manually operable switch for normally preventing response ofsaid actuating means to said triggering signals but operable to permitresponse thereto. 5. In an electronic defibrillator of the typeemploying first capacitor means for storing high voltage electricalenergy supplied from a direct current energy source and a pair ofelectrodes for discharging said stored energy through a patient, theimprovement comprising:

sensing and control circuit means, including a first transistor switchhaving emitter, base and collector electrodes, a relay having contactscoupled to said energy source and having an energizing coil coupled tosaid collector electrode and operative upon conduction of said firsttransistor switch, and voltage sensing apparatus coupled between saidfirst capacitor means and said base electrode to apply a signal to saidbase electrode related to the voltage across said first capacitor means,for alternately enabling and disabling said direct current source inresponse to the value of the voltage across said first capacitor meansfor maintaining the energy stored in said first capacitor means at apreselected level; switch means normally coupling said first capacitormeans to said direct current energy source but actuable to couple saidfirst capacitor means to said pair of electrodes;

and actuating means, including a second transistor switch, for applyinga signal of a predetermined potential to both said emitter electrode ofsaid first transistor and to said switch means for concurrentlyinhibiting operation of said first transistor switch and for actuatingsaid switch means.

6. The combination according to claim 5 and further comprising a cardiacsignal amplifier having an input circuit adapted to be coupled to apatient for developing an amplified output of the electrical activity ofthe beats of the patients heart, a synchronizing signal amplifiercoupled to said cardiac amplifier for developing triggering signalsbearing a predetermined phase relation to the beats of the patientsheart, means for applying a triggering signal to said actuating meansfor operating said actuating means, and inhibiting means coupled to saidactuating means and responsive to said predetermined potential uponoperation of said actuating means for 10 preventing further effectiveoperation of said synchronizing signal amplifier.

References Cited UNITED STATES PATENTS 3,236,239 2/1966 Berkovits128-419 WILLIAM E. KAMM, Primary Examiner.

